TITLE: GCN CIRCULAR NUMBER: 16141 SUBJECT: GRB 140419A: Mondy optical observations DATE: 14/04/22 14:44:54 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Volnova (IKI), E. Klunko (ISTP), M. Eselevich (ISTP), I. Korobtsev (ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 140419A (Marshall et al., GCN 16118) with AZT-33IK telescope of Sayan observatory (Mondy) on Apr. 19-21. We took several images in R-filter of 60 s exposure. On stacked images we clearly detected the optical afterglow (Zheng et al., GCN 16119; Guver et al., GCN 16120; Butler et al., GCN 16121; Kuin et al., GCN 16123; Hentunen et al., GCN 16126) except the combined image of Apr. 19 due to unfavorable weather conditions. Our photometry is consistent with the decaying law derived from RATIR observations (Littlejohns et al., GCNs 16139, 16136). The details of the photometry are the following: date UT start t-T0 Filter Exp. OT Uplim (mid, days) (s) 3sigma 2014-04-19 16:26:35 0.52030 R 10*60 n/d 19.3 2014-04-20 14:49:15 1.47495 R 83*60 21.12 +/- 0.10 21.6 2014-04-21 14:58:36 2.49015 R 107*60 21.60 +/- 0.15 22.2 The photometry is based on nearby SDSS star, R (gri -> R transformations by Lupton 2005): SDSS id R J082752.69+461357.4 17.381 +/- 0.018